Technical Field
Devices and methods for a delivering a material into an orthopedic target site are disclosed. For example, devices and methods for delivering bone cement to a vertebral body are disclosed.
Description of Related Art
It is common during orthopedic medical procedures to place materials in the bone. For instance, in vertebroplasty, bone cement is injected to stabilize a vertebral compression fracture. Similarly, in kyphoplasty, a balloon is first inserted into a vertebral body and inflated to create a void. The void is then filled with bone cement.
Some devices for moving bone cement consist of a hand pump and a flexible tube. The tube is inserted into the orthopedic structure and bone cement is pumped through the tube and into the structure. The tube is long enough that the pump may be located up to several feet from the injection site. These devices have the advantage of allowing the physician to be removed from the injection site such that he or she is not exposed to the x-rays used to guide the filling procedure. However, tactile feedback is poor, excessive pressures can be generated and the bone cement remaining in the tube is all wasted in the end. Detaching the tube from the mass of injected bone cement can also be problematic.
Some devices, such as those used for kyphoplasty, use a simple rigid hollow tube with a solid rigid pusher rod that slides down the tube. The hollow tube is filled with bone cement and the solid pusher rod drives the bone cement into the body. These devices have the advantage of excellent tactile feedback, simplicity, lack of waste and easy termination with the mass of injected bone cement. However, they have small volumes and, because they are used right at the injection site, may expose the physician to x-rays during the filling procedure. Finally, because of their material choices, they may require significant force to extrude cement as the cement hardens.
What is needed is a device to place material into bone that protects physicians from X-ray exposure, has adequate volume, smooth operation, good haptics, minimizes waste and allows easy termination with the mass of injected bone cement.